This application seeks support for 2 years of data analysis of a unique data set consisting of both members of each of 1,033 pairs of female same- sex twins from the population-based Virginia Twin Registry and 1,470 of their surviving parents. Data analysis will include the assessment of lifetime history of alcohol dependence and of 5 major common psychiatric disorders (major depression, generalized anxiety disorder, panic disorder, phobia, and eating disorders). The twins have had 3 waves of evaluation at yearly intervals (questionnaire, face-to-face interview, plus questionnaire and phone interview); the parents have been seen once (face-to-face interview plus questionnaire). The proposed analyses, which will use state-of-the-art statistical and genetic methods, will produce important advances in the understanding of the etiology of alcohol dependence in women. Major goals of this project include: 1) quantifying the role of genetic and environmental factors in the etiology of alcohol dependence in women, ii) using multivariate twin methods to clarify the degree to which comorbidity between alcohol dependence and other major common psychiatric disorders (e.g., depression) in women results from shared genetic factors (e.g., genes that influence the liability to both depression and alcohol dependence), shared familial environment (e.g., aspects of the rearing environment that are pathogenic for both depression and alcohol dependence) or individual-specific environmental factors that predispose to both disorders, and iii) employing the twin-family design, including specific measures of potential environmental risk factors (e.g., parental social class, religious affiliation and rearing styles), to understand the genetic and environmental mechanisms involved in the parent-offspring transmission of the vulnerability to alcohol dependence. These analyses will lay the groundwork for a followup study of this cohort, which will include more detailed assessments of alcohol dependence and related risk factors.